The human race has been fascinated with the vast sea of space for as long as our first flickers of awareness that it even existed began to form. Specifically, one very profound question that has gestated within our collective consciousness is simply: are we alone? We have long pondered whether there might be someone else out there amongst that uncharted ocean of stars, and this has become the focus of science fiction stories, personal reflection, philosophical dilemma, and scientific debate from the time we were able to comprehend that there were even other planets out there. In recent years our ever advancing technology has allowed us to peer into the deep black of space and locate many other planets orbiting stars just as our own, with quite a few even displaying signs that they may even be similar to ours and be habitable, and for decades we have carefully listened in to hear if there is any message flying about in the void. But is there anyone there at all?
The question of whether there is other advanced life out there is a profound one, and perhaps one of the most important unanswered questions there is. Another is, if intelligent life is out there, then where are they? We have spent vast amounts of time looking for such life, used millions upon millions of dollars, and made great sacrifices exploring the great unknown beyond our world, scouring every corner of the known universe for any sign whatsoever of life, and yet as far as we know we are the only ones. How could this be? There are ideas.
In 1950, influential and notable physicist Enrico Fermi was working for Los Alamos National Laboratory, and one day while having lunch with colleagues Emil Konopinski, Edward Teller and Herbert York, the conversation came around to UFOs and alien life. The group began discussing the possibility of other alien civilizations out there scattered across the galaxy, and that was when Fermi simply and bluntly asked “Where are they?” This generated a bit of laughter around the table, but he was perfectly serious. When the others asked exactly what he had meant, Fermi explained that if there was another civilization or civilizations that had developed out there with the technological ability to traverse space, then eventually they should have already spread out all over the galaxy, and we should have had some brush with them by now in some form.
Fermi reasoned that there had been plenty of time for them to do so, and utilized complicated equations to illustrate that over millions and millions of years, just a drop in the bucket compared to the age of the universe, these hypothetical alien civilizations should have at least found us by now. Fermi explained that with so many stars and potential planets in the observable universe, then if even a fraction of those had produced intelligent, spacefaring life then they would have exponentially broken their barriers and moved out into the galaxy, colonizing new worlds, and we would have surely known about them by now. By Fermi’s various calculations, the probability for intelligent life somewhere in the universe was high considering the sheer scale of it all, and if such advanced societies had developed, then after so much time aliens should be everywhere by now, or at the very least given us some sort of sign of their existence, even if such societies are rare. Yet there is no one, no evidence of such a thing, not a single sign that there is anyone else out there at all. Essentially, like Fermi asked, where is everybody?
This is the main gist of what has gone on to become known as the “Fermi Paradox,” and although it has been criticized by many as being perhaps too simplistic and making too many assumptions based on our own ideas of life, it has nevertheless gone on to become a major cornerstone for debate on the topic of intelligent life elsewhere in the universe, and has inevitably hung over most discussions on the matter. This offhand lunchtime remark has propelled the imagination and driven the efforts of organizations like SETI. No matter what one thinks of the veracity of Fermi’s question, it is a compelling one to say the least, and there have been many numerous and varied theories that have come forth to try and explain just why we have not found anyone else out there in this cold universe of ours.
Perhaps the most intuitive and ready answer is that the universe is simply too incredibly huge, and that these beings are just too incalculably far away. Perhaps we, or them, live in the boondocks of the universe, the outer fringes, and with scales like these we are talking about with distances and areas so vast that the average person would have trouble even comprehending it all, it seems quite possible. Imagine the galaxy as a sprawling beach of white sand, and the universe as every beach in the world and you are getting somewhat close. Now imagine someone in, say, South Africa trying to find one particular single grain of sand on some remote beach in North America. These are the kinds of vast scopes we are dealing with here, even more so.
In this theory, we are simply too far away and too lost in the cosmos to even register. We could just be out in the middle of nowhere amidst a beach of stars and no one has noticed us. We might just be in an isolated, uncharted corner of the universe and while all the other intelligent races out there are getting together we simply remain undiscovered. This seems like a rational idea, and could be true, but Fermi didn’t think this cut the mustard. He was under the impression that distance mattered little, nor did the speed of travel. The SETI Institute’s very own web page says of this:
You can quibble about the speed of alien spacecraft, and whether they can move at 1 percent of the speed of light or 10 percent of the speed of light. It doesn't matter. You can argue about how long it would take for a new star colony to spawn colonies of its own. It still doesn't matter. Any halfway reasonable assumption about how fast colonization could take place still ends up with time scales that are profoundly shorter than the age of the Galaxy. It's like having a heated discussion about whether Spanish ships of the 16th century could heave along at two knots or twenty. Either way they could speedily colonize the Americas.
This could be explained away by saying that life may just be incredibly rare in the universe, which when coupled with the immense distances involved serves to keep us apart, but even if this were the case there is also the fact that these would be races far beyond us in terms of development, so would we really remain merely out of sight in some remote corner of the universe without being detected in the slightest? Is this possible? Indeed, we have been boldly announcing our presence to the universe for decades, so are they so far away that they haven’t received the message or what? Perhaps, or maybe they do know we are here but simply don’t care. Maybe they are listening to our desperate calls out into the cosmos but just don’t want to answer?
There are a lot of reasons why these hypothetical aliens might not want to acknowledge our existence. Perhaps we just seem to be too primitive, and they no more wish to try and talk to us than we might wish to try and talk to an ant. As renowned astrophysicist Neil deGrasse Tyson has said, “We’d be drooling, blithering idiots in their presence.” More optimistically, maybe they are listening, but waiting until we reach a certain level of sophistication before finally approaching us. Or maybe they see us as an inevitable threat and have decided to stay away. More depressingly, maybe we just aren’t all that interesting to them. Who knows? It also could be that they see us as merely a curiosity, and are watching but willfully choose to leave us be as we are, just watching us and seeing what happens next. This theory even has a name, the “Zoo Hypothesis,” first suggested by a John A. Ball in 1973, which suggests that we are at best curiosities for other civilizations and at worst not worth talking to or insignificant, just entertainment and nothing more. Ball would say of this idea:
The idea that we shall be welcomed as new members into the galactic community is as unlikely as the idea that oysters will be welcomed as new members into the human community. We’re probably not even edible.
It seems to be a slap in the face, that we could spend so much time and money more or less blaring out our presence into the stars without an answer simply because they choose to ignore us or blow us off for whatever reasons. If that seems too depressing for you, then an offshoot of this is that we are just using the wrong method of communication to reach out to them. Although using radio waves seems natural and rational to us, there is the chance that they have moved well beyond such primitive methods of broadcast, or have never even developed this means of communication at all. Maybe they are using some other advanced system of communication and are so far beyond our own attempts at contact that they simply don’t recognize our signals for what they are. This could work the other way around as well, with them potentially sending out copious messages out into the stars but with us unable to detect or understand them to any extent. One cosmologist and astrophysicist named Lord Rees has observed:
They could be staring us in the face, and we just don’t recognize them. The problem is that we’re looking for something very much like us, assuming that they at least have something like the same mathematics and technology. I suspect there could be life and intelligence out there in forms we can’t conceive.
In short, we might mutually have no idea that the other is trying to communicate, and our messages just might turn out as white noise to each other. Other reasons for no response from the cosmos could also be that we just haven’t been looking long enough or have been focusing on the wrong places, but the fact that we have gotten no response to our various dedicated efforts to reach out seems at least somewhat discouraging.
Other theories prove to be a slight bit more dismal and sobering yet. One very persistent theory is that intelligent life has routinely developed throughout the cosmos, but that they have inevitably hit a dead end or stumbling block along the way. According to this idea, it is the intrinsic nature of an advanced species to eventually destroy or cripple itself, or reach point where it is otherwise unable to continue its journey out into the stars. There are two different takes on this idea. One is that advanced societies are inherently self-destructive; an idea called the Medea Hypothesis, named after a Greek goddess who killed her own children. According to this hypothesis, any sufficiently developed civilization will eventually totally wipe itself out through warfare, violence, genocide and strife.
It is not hard to see this in effect to some extent even within the news of our own current affairs, so perhaps no aliens have gotten far enough to reach us because they just have it wired into their genes to annihilate themselves before they ever even get the chance. They simply self destruct at some point, never progressing past a certain point of development. Or maybe other species out there have indeed reached past this point, but none that have overlapped in the same era before fading away. After all, we are talking about mind-bogglingly long stretches of time, so maybe they have just naturally run their course and reached an end before another intelligent civilization comes about to talk to, but in the end there has been something that has caused the extinction of an intelligent race to make it uncontactable.
Another take on this basic premise is called the “Great Filter Theory,” which holds that intelligent life is, for one reason or another, simply not able to progress to the point of intergalactic travel and communication. It supposes that we eventually reach some form of a barrier to our inexorable technological advances that keeps us tethered to our own world and unable to reach out into the cosmos to any appreciable degree. This could be because of many reasons, such as war, ecological catastrophe, a cataclysmic event, or the limits of our minds, but it all boils down to us inevitably hitting an impenetrable wall through which we cannot pass. That species are doomed to fail at reaching out into the stars is unsettling to say the least, but on a brighter note maybe we are just the first ones to have managed to breach this limit?
There are some who think so, but if this is the case and we are truly the first, then all other life in the universe would be far too primitive to have reached our level of sophistication and so would remain incognito for quite some time to come, essentially making us effectively alone. If this is the case, then we are truly the first intelligent beings to make it to the point where we are flying out into space and making attempts at communication, but no one else has the ability to listen. This relative primitive state of affairs could explain why no other civilization has been sending signals into space or answering our own, because they still simply lack the means with which to do so, and we may be waiting for quite some time.
Linked to this is the idea that alien life may be simply far too different from ours to even recognize. We like to think that we have a handle on what constitutes life and its building blocks, or the criteria for a hospitable world, but what if we have it all wrong? What if life does not have to abide by our own tentative understanding of its rules, and we are more or less anthropomorphizing it to fit our own limited window for what life requires or should be like? If this were the case alien life could be all around us and blaring into our ears and we would not recognize it in the slightest bit because it would be too different from our limited definition of what life should be for us to recognize it as such. It could just be incomprehensible to us.
Moving out into more far-out territory we come to more, shall we say, unconventional explanations for our lack of any sort of contact with extraterrestrials. One common one is that we are all living in a simulated reality and therefore aliens don’t exist simply because they have not been programmed in. There is actually a lot of speculation on this matter, of which I have covered at Mysterious Universe before, and as questionable as it all may seem it would definitely explain why there are no aliens. Similar to this is the idea that aliens do exist, but that they live in another plane of reality, and therefore remain mostly hidden to us. They may even be all around us right now, but we would never know because they are invisible and lurking in another dimension or plane of existence just beyond our perceptions.
There is also of course the notion that alien life is already here, as evidenced by all of the UFO sightings and alien encounters we have recorded over the decades. Maybe we have to look no further than these reports to see the evidence that not only does alien life exist, but that it is already here amongst us, just remaining in the shadows hidden, elusive and unverified. Although there are certainly a lot of strange UFO sightings and reports of meetings with aliens, these nevertheless remain unconfirmed, and even if they are all real they could be something even stranger still, and not necessarily evidence of life from the stars.
Finally we have what might be the bleakest, most depressing answer to the Fermi Paradox of all, and that is that we truly are alone. Although that may seem unbelievable considering the countless planets that apparently lie out there in the universe, perhaps we just happened to win the intergalactic lottery. Despite all of the talk of the building blocks of life present on other worlds, perhaps things were able to come together just so and in such a precise manner on our planet that life was able to evolve, but hasn't done so anywhere else. There is the possibility that this was a one of a kind occurrence, an anomaly, and that even if it were to happen again there would be no guarantee that it would ever advance past single-celled organisms. In this scenario we are truly the only ones, the only advanced race in the entire universe, indeed perhaps the only life at all, and the reason no one has answered our calls or shown up at our doorstep is that there is simply no one else out there, just the yawning chasm of endless, inhospitable, empty space. It is a chilling revelation to be sure, and with all of the potential for life lying out there in the chasms of space a seemingly unbelievable one, yet one that must be at least considered; that maybe, just maybe, we are alone after all.
There are other ideas as well, running the range from the rational to the absurd, but these are the main theories as to why we have yet to officially encounter any aliens or even detect them in the slightest bit. We continue to trudge on as we always have, the dedicated amongst us reaching out to the stars and trying to elicit a response, and that response never comes. Why is it that we have never found any evidence of life beyond our own? Why have we remained alone and uncertain as to our status in the universe? Is the answer right around the corner, or is it as some suspect that we are the only life there is in this unfathomably large universe; the exception to the rule and the sole consciousness within an infinite sea of dark, lifeless emptiness? Until we make the contact we yearn for, we will not know.